Metabolism/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby. A man, Tim, is in a kitchen. There are racks of plates and spices in the background. On the countertop in front of Tim is a container of milk. Tim is wearing a white T-shirt containing an image of intestines. Tim is holding a cereal box labeled Frosted Corn Pellets. Tim is trying to pour the contents of the box into a bowl on the countertop. An envelope comes out of the box and lands in the bowl. TIM: Moby, did you eat all my cereal? The view switches to a robot, Moby, sculpturing a boat from cereal flakes and other foodstuff. There are blue lights on Moby’s chest that blink on and off. MOBY: Beep. TIM: That’s … really great. Tim takes a sheet of paper out of the envelope. Tim reads from the typed letter. TIM: Dear Tim and Moby, Why do I need to eat breakfast? From, Mayle. TIM: All living organisms need energy for their cells to grow and function. The view changes to Tim speaking in front of a wall with colored stripes. Drawings of the following animals appear: a bear, a duck, a snake, a pelican, a fish, a bee, and a rabbit. TIM: Eating food is how animals, including humans, get that energy. The screen splits into two frames. In the left frame, a boy is eating meatballs from a plate. In the right frame, a cow is chewing grass out of a feed bin. TIM: Once food has been eaten, it’s processed through a series of chemical reactions that we call metabolism. Metabolic reactions fall into one of two categories: catabolic and anabolic. Then the scene reverts back to Tim and Moby in the kitchen. The container of milk is still on the countertop, along with the empty bowl. Text reads: metabolism. TIM: Catabolic reactions break down complex molecules from your food into simpler molecules, releasing energy in the process. An animation of a cluster of many different colored spheres, representing a molecule, is shown. They are black, white, and red spheres. A starburst covers the cluster, flashes, and disappears. The cluster has now separated into five smaller clusters. Two of the clusters are comprised of two white spheres attached to one end of a red sphere. Three of the clusters are comprised of one black sphere and two red spheres. These three spheres are arranged in a row with the black sphere in the center of the two red spheres. Text reads: catabolic. TIM: Anabolic reactions use that energy to build other complex molecules from the simple molecules. A starburst covers the five clusters, flashes, and disappears. The five clusters have now become one large cluster. Text reads: anabolic. The scene switches back to Tim and Moby in the kitchen. MOBY: Beep! TIM: Yeah, I guess you could say that catabolism powers anabolism! TIM: Cellular respiration, the process in which glucose is broken down, is an example of a catabolic reaction. An animation shows the shadow of a man. His mouth, esophagus, stomach, and intestines are shown. A line from the stomach leads to an inset of an enlarged view of the contents. In the inset, is a long chain of molecules moving downward while clusters of molecules separate from the end. The smaller clusters of molecules leave the screen. Text reads: cellular respiration. TIM: Glucose is a kind of sugar we get from food. A single molecule is shown. Text reads: glucose. Yellow rings form around the molecule, expand, and disappear. TIM: It’s the main source of fuel for the body’s cells. Inside the part of a cell known as the mitochondrion, glucose is split up into simpler molecules like carbon dioxide and water. A view of a cell appears. The animation zooms in on an object within the cell that looks like a mouth with teeth. An enlarged view of an inset from within the object appears. Text reads: mitochondrion. The inset shows a molecule consisting of many red, black, and white spheres clustered together. Around this molecule appear a number of molecules consisting of two red spheres. These molecules move towards the larger molecule and join to it. This enlarged molecule splits. In the center is a circle around a lightning bolt with the label, UpperWord A T P. The spheres are now arranged into two shapes. There is a group of three spheres arranged in a row with a black sphere in the center and a red sphere on either end. The other is a group of three spheres with a red sphere in the center and two white spheres attached to one end. TIM: Energy is released in the process. The view returns to show Moby whose lights are blinking. MOBY: Beep? The view pans out to show Tim and Moby in the kitchen. TIM: Right. The energy that comes from that reaction is used to keep cells healthy and grow new ones. That’s when anabolism comes in. Anabolic reactions are ones that build up molecules that help our cells multiply and stay in good working condition. An animation of a cell fills the screen. It has a membrane and a central nucleus in the shape of an oval. The nucleus splits apart and forms two ovals. Then the cell itself expands and splits apart into two pieces. One oval goes with each piece. The final result is two cells, each with its own nucleus. The view of Tim and Moby returns. TIM: Things like bone and muscle growth all come from anabolic reactions. MOBY: Beep? TIM: Well, plants have metabolisms, too, but they don’t need to eat food for energy. Several plants are shown. TIM: Instead, they make their own food through a process called photosynthesis. A close-up of one of the leaves appears. Dashed yellow lines representing sunlight fall onto the leaf. Text reads: photosynthesis. TIM: Plants use their roots to drink up water from the soil, while their leaves absorb carbon dioxide from the air. Moby can be seen on hands and knees examining the soil at the base of a tree. Then an image of a plant with many green leaves is shown. TIM: The leaves also absorb sunlight, storing its energies in special structures called chloroplasts. A spot on one of the leaves enlarges to show a view of four structures, each resembling a stack of four poker chips, connected by green tubes. Text reads: chloroplasts. TIM: These contain a green pigment called chlorophyll, which traps photons of sunlight. When energy from those photons is combined with carbon dioxide and water, it triggers a chemical reaction. An animation shows a lightning bolt in the center of the screen, labeled UpperWord A T P. There is a group of three spheres arranged in a row with a black sphere in the center and a red sphere on either end. There is another group of three spheres with a red sphere in the center and two white spheres attached to one end. The row of black and red spheres flashes then the cluster of red and white spheres flashes. Then all the spheres join together forming a cluster that moves under the lightning bolt and disappears from the screen. TIM: The products of this anabolic reaction are oxygen and glucose. The animation shows a flash. The molecules appear back at the center of the screen and begin to spread outward. Red spheres, which flash briefly, are arranged in groups of two representing oxygen molecules. The glucose remains in the center and is shown as a large cluster of red, black, and white spheres. It also flashes briefly. The view comes back to Moby. MOBY: Beep? TIM: Good point! Tim and Moby are standing in the kitchen. The milk container is still on the tabletop. The bowl is empty. TIM: Besides being a main source of nutrition for the plants, the glucose can also provide some much-needed energy to any animal that decides to make a meal out of the plant! We hear a stomach growling and Tim moves his hand to his stomach. TIM: Speaking of meals … I need some breakfast. The scene fades out and when it fades back in, Moby has a napkin over his right arm. With his left hand, he lifts a hemispherical cover up from a plate revealing the boat he had sculpted earlier. TIM: Okay, I’m not eating that. MOBY: Beep. TIM: No way, there's glue in there! Ahhh! Get away! Tim and Moby flee off the right side of the screen as the animation fades to black. Category:BrainPOP Transcripts Category:BrainPOP Health Transcripts